The role of magnetic fields in the scattering of p-modesA. Gascoyne and R. Jain
Applied Mathematics Department, The University of Sheffield, S3 7RH, UK
Received 23 January 2009 / Accepted 13 May 2009
Aims. We determine the direct and indirect effects of magnetic field on p-mode scattering.
Methods. We solve a set of magnetohydrodynamic equations using the Born approximation to determine phase shifts in p-modes due to a region of inhomogeneity. The region of inhomogeneity is a magnetic flux tube with the characteristics of flaring field lines. This enables us to investigate the magnetic field effects on the phase shifts.
Results. The magnetic configuration of our flux tube model plays a vital role in the phase shifts of p-modes. The suppression of sound speed and pressure within the flux tube region is not the only factor to consider in the scattering of p-modes. There is a direct effect of the magnetic fields caused by the flaring of field lines on phase shifts.
Key words: sun: magnetic fields -- sun: helioseismology -- sun: oscillations -- magnetohydrodynamics (MHD) -- scattering
© ESO 2009